An ORC-TEG combined geothermal power generation system

Abstract

The application provides an ORC-TEG combined geothermal power generation system, which comprises a heat source loop, a heat source and an evaporator being connected in series on the heat source loop; an organic working medium loop, the evaporator, a turbine generator and a condenser being arranged on the organic working medium loop; a TEG-preheater and a TEG-reheater; the TEG-preheater and the TEG-reheater are both thermoelectric power generation assemblies, the thermoelectric power generation assembly comprises a cold end heat exchanger, a hot end heat exchanger and a plurality of thermoelectric modules being arranged between the two heat exchangers; the hot end heat exchanger of the TEG-preheater is connected to the heat source loop between the heat source and the evaporator, and the cold end heat exchanger thereof is connected to the organic working medium loop between the evaporator and the cold end heat exchanger of the TEG-reheater; the hot end heat exchanger of the TEG-reheater is connected to the organic working medium loop between the turbine generator and the condenser, and the cold end heat exchanger thereof is connected to the organic working medium loop between the condenser and the cold end heat exchanger of the TEG-preheater. Through the system provided by the application, the net power generation of the geothermal power generation system and the energy comprehensive utilization efficiency are improved.

Description

Technical Field

[0001] This application relates to the field of geothermal power generation technology, and in particular to an ORC-TEG combined geothermal power generation system. Background Technology

[0002] Among medium- and low-temperature geothermal power generation technologies, the Organic Rankine Cycle (ORC) power generation technology has a relatively high level of maturity, while the application of Thermal Photovoltaic (TEG) in this field is still in its early stages. Currently, the power generation efficiency of ORC technology is about 10%, and the thermoelectric conversion efficiency of TEG is less than 5%, resulting in poor economic performance for medium- and low-temperature geothermal power generation, making it uncompetitive compared with clean energy power generation technologies such as wind, solar, and hydropower.

[0003] To improve the efficiency of medium- and low-temperature geothermal power generation, related technologies connect TEG (thermoelectric generator) and ORC (oral regenerative thermal radii) systems in series. By extracting heat from the heat source, the overall power generation capacity of the combined system and the comprehensive utilization efficiency of geothermal resources are increased. However, due to the inherent properties of current thermoelectric materials, specifically their ZT (thermometric figure of merit) values, which are generally below 2, placing the TEG system after the ORC system results in very low power output due to the limited temperature difference. While placing the TEG system before the ORC system allows for higher power output under large temperature differences, it cannot compensate for the reduced power output of the ORC. Furthermore, the cooling system required to maintain the temperature difference between the hot and cold ends of the TEG system generates additional power consumption, further reducing the net power output of the combined power generation system. This severely restricts the widespread application of ORC, TEG, and other power generation technologies in the field of medium- and low-temperature geothermal power generation. Summary of the Invention

[0004] To address the aforementioned issues, one of the objectives of one or more embodiments of this application is to provide an ORC-TEG combined geothermal power generation system to improve the net power generation and overall energy utilization efficiency of the geothermal power generation system.

[0005] This invention provides an ORC-TEG combined geothermal power generation system, the technical solution of which is: An ORC-TEG combined geothermal power generation system, the system comprising: A heat source circuit, wherein a heat source and an evaporator are connected in series in the heat source circuit; An organic working fluid circuit, wherein the evaporator, turbine generator and condenser are provided on the organic working fluid circuit; The heat source circuit and the organic working fluid circuit share a TEG preheater, and the organic working fluid circuit is also equipped with a TEG regenerator; both the TEG preheater and the TEG regenerator are thermoelectric power generation components, and the thermoelectric power generation components include a cold end heat exchanger, a hot end heat exchanger, and several thermoelectric modules sandwiched between the two. The hot end heat exchanger of the TEG preheater is connected to the heat source circuit between the heat source and the evaporator, and its cold end heat exchanger is connected to the organic working fluid circuit between the evaporator and the cold end heat exchanger of the TEG regenerator. The hot end heat exchanger of the TEG-regenerator is connected to the organic working fluid circuit between the turbine generator and the condenser, and its cold end heat exchanger is connected to the organic working fluid circuit between the condenser and the cold end heat exchanger of the TEG-preheater. The TEG-regenerator uses the high-temperature working fluid with residual heat after expansion by the turbine generator in the organic working fluid circuit as the hot end and the low-temperature working fluid after condensation by the condenser in the organic working fluid circuit as the cold end; the TEG-preheater uses the high-temperature heat source in the heat source circuit as the hot end and the low-temperature working fluid in the organic working fluid circuit as the cold end; the two thermoelectric power generation components respectively utilize the temperature difference between the cold end heat exchanger and the hot end heat exchanger to generate electricity from the thermoelectric module and supply power to at least one energy-consuming device in the heat source circuit and the organic working fluid circuit.

[0006] Optionally, in the heat source circuit, the heat source, the first pump, the evaporator, and the hot-end heat exchanger of the TEG preheater are sequentially connected in a loop; In the organic working fluid circuit, the second pump, the cold end heat exchanger of the TEG-regenerator, the cold end heat exchanger of the TEG-preheater, the evaporator, the turbine generator, the hot end heat exchanger of the TEG-regenerator, and the condenser are sequentially connected in a loop.

[0007] Optionally, the system further includes: A cold source circuit, wherein a third pump, the condenser and the cooling tower are sequentially connected in a circulating manner; The thermoelectric power generation component is electrically connected to at least one of the first pump, the second pump, and the third pump, and / or the cooling tower, so as to directly supply the generated electrical energy to the corresponding pump and / or the cooling tower.

[0008] Optionally, in the thermal photovoltaic power generation module: The cold-end heat exchanger is annular, and multiple sets of cold flow channels are formed inside along the annular contour. Each set of cold flow channels includes a cold flow channel extending along the axial direction. The hot-end heat exchanger is plate-shaped and has an axially extending hot flow channel inside. Multiple hot-end heat exchangers and thermoelectric modules are provided, and each thermoelectric module is sandwiched between the location of each group of cold flow channels of the cold-end heat exchanger and the corresponding hot-end heat exchanger.

[0009] Optionally, the cold-end heat exchanger is provided with a flow-dividing ring cavity and a flow-collecting ring cavity at both ends, the flow-dividing ring cavity is connected to the cold-end fluid inlet manifold, and the flow-collecting ring cavity is connected to the cold-end fluid outlet manifold; a plurality of cold flow channels are connected between the flow-dividing ring cavity and the flow-collecting ring cavity; The cold-end heat exchanger is provided with a fixed base on the symmetrical plane of the cold-end fluid inlet manifold and the cold-end fluid outlet manifold.

[0010] Optionally, the two ends of the hot-end heat exchanger are connected to the hot-end fluid inlet manifold and the hot-end fluid outlet manifold respectively via flexible hoses, and the flow holes on the hot-end fluid inlet manifold and the hot-end fluid outlet manifold are arranged in a circular pattern.

[0011] Optionally, the annulus includes a polygon, and each group of cold runners corresponds to each sidewall of the polygon; the plate shape includes a flat plate shape, and the plate surface profile of the flat plate shape fits the wall surface profile of the sidewall.

[0012] Optionally, a flat plate-shaped heat exchanger is arranged on the inner and outer ring edges of each of the sidewalls, and two heat exchangers located on opposite sides of the same sidewall are arranged in a mirror image relative to the sidewall. In this configuration, two hot-end heat exchangers arranged in a mirror image are radially fixed to the cold-end heat exchanger by fasteners, and each set of thermoelectric modules is sandwiched between each sidewall and each hot-end heat exchanger.

[0013] Optionally, the cold flow channels in each of the side walls are direct flow channels, and the number of direct flow channels in the side walls farther away from the cold end fluid inlet increases sequentially, so as to make the flow distribution of each side wall uniform; The hot flow channel in the hot end heat exchanger is a direct flow channel, and a conical header with a flow splitting structure is provided at the fluid inlet. The conical header is configured to distribute the fluid entering the hot end heat exchanger evenly to each of the direct flow channels. The fluid refers to the high-temperature working fluid or the high-temperature heat source.

[0014] Optionally, a thermally conductive interface material is coated between the cold-end heat exchanger and the thermoelectric module, and between the hot-end heat exchanger and the thermoelectric module.

[0015] Compared with the prior art, this application has the following advantages: The system provided in this application integrates TEG into the preheater and regenerator of the ORC system, using the organic working fluid itself as the cold end cooling medium of the TEG. This eliminates the need for additional cooling systems and circulation equipment, avoiding additional power consumption. Furthermore, it utilizes the preheating and reheating processes to recover the waste heat of the heat source and working fluid for cascade power generation, thereby improving the net power generation and overall energy utilization efficiency of the combined system.

[0016] The thermoelectric power generation module provided in this application uses a ring-shaped cold-end heat exchanger in conjunction with a plate-shaped hot-end heat exchanger, with a thermoelectric module sandwiched between the two. This significantly increases the number of thermoelectric modules, improving the system's compactness and power generation efficiency. Furthermore, through optimized design of the cold and hot flow channels, the flow distribution is made uniform, mitigating the problem of localized overcooling or overheating at the heat exchange interface and enhancing the TEG's power generation efficiency and stability. Attached Figure Description

[0017] To more clearly illustrate the technical solution of this application, the drawings used in the description of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a system architecture diagram of the ORC-TEG combined geothermal power generation system according to an embodiment of this application; Figure 2 This is a three-dimensional structural diagram of a photovoltaic power generation component according to an embodiment of this application; Figure 3 yes Figure 2 Cross-sectional view at point A; Figure 4 This is a structural diagram of the cold-end heat exchanger according to an embodiment of this application; Figure 5 This is an internal cross-sectional view of the hot-end heat exchanger located on the outer sidewall according to an embodiment of this application; Figure 6 This is an external outline view of the hot-end heat exchanger located on the inner side of the sidewall according to an embodiment of this application; Figure 7 This is a three-dimensional structural diagram of the hot-end fluid outlet manifold or hot-end fluid inlet manifold according to an embodiment of this application.

[0019] Explanation of reference numerals in the attached figures: 1. Pump; 2. Heat source; 3. TEG preheater; 4. Evaporator; 5. Expander; 6. Generator; 7. TEG regenerator; 8. Condenser; 9. Cooling tower; 10. Cold end heat exchanger; 101. Cold runner; 11. Hot end heat exchanger; 111. Hot runner; 112. Conical header; 113. Flow hole; 12. Thermoelectric module; 13. Hot end fluid inlet manifold; 14. Hot end fluid outlet manifold; 15. Cold end fluid inlet manifold; 16. Cold end fluid outlet manifold; 17. Diverting ring cavity; 18. Collecting ring cavity; 19. Hose; 20. Fixed base; 21. Fastening bolt; 22. Through hole; 23. Nut. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] It should be noted that before describing the technical solution of this application in detail, the current state of the prior art and its limitations will be further explained in order to facilitate understanding of the improvements made by the technical solution of this application compared with the prior art.

[0022] There are existing solutions for combined power generation using TEG and ORC. One proposed system integrates TEG and ORC by embedding the TEG inside the condenser 8 of the ORC system. It utilizes the temperature difference between the working fluid at the expander outlet and the cooling medium to generate electricity, recovering waste heat from the working fluid while simultaneously cooling it. The electricity generated by the TEG powers the compressor pump, reducing the auxiliary power consumption of the ORC system. However, this system has drawbacks: maintaining the temperature difference across the TEG inevitably reduces the cooling effect of the condenser 8, leading to insufficient cooling of the working fluid at the expander outlet and negatively impacting ORC operation. Conversely, maintaining a high condensation effect results in a low temperature difference across the TEG, leading to poor output performance and reduced overall system benefits. In other words, this solution presents a trade-off between condensation efficiency and temperature difference power generation, making it difficult to achieve both simultaneously.

[0023] Another proposed waste heat recovery system for marine diesel engines based on a combination of TEG and ORC (Organic Heat Recovery). This system consists of four sub-cycles: a diesel engine cooling circuit, an ORC waste heat power generation circuit, a TEG waste heat power generation circuit, and a seawater cooling circuit. In this system, the high-temperature exhaust gas from the diesel engine flows sequentially through the air compressor turbine, the TEG hot end, and the evaporator. The coolant absorbs energy from the TEG hot end before entering the preheater to preheat the ORC working fluid. Seawater is used to cool both the diesel engine coolant and the ORC working fluid. However, this scheme requires a separate coolant circuit for the TEG, resulting in a complex system structure, numerous auxiliary devices, and the failure to further integrate the TEG into the ORC system's preheater and regenerator, thus failing to achieve cascaded energy utilization of the heat source and working fluid during the preheating and regeneration stages.

[0024] It is evident that the ORC-TEG combined power generation schemes in related technologies generally suffer from the following common problems: First, improper integration of the TEG and ORC may result in limited TEG temperature difference leading to low power generation, or reduced ORC power generation; second, the TEG requires an independent cooling system, generating additional power consumption and weakening net power output; and third, the temperature difference between the preheater and regenerator is not fully utilized for cascaded power generation. Therefore, there is an urgent need for a combined power generation scheme that can rationally integrate the TEG into the ORC system, requires no additional cooling power consumption, and enables cascaded utilization of heat source 2 and working fluid energy.

[0025] To facilitate understanding, the following explanations are provided for some of the terms used in this application: ORC refers to the Organic Rankine Cycle, a Rankine power cycle that uses a low-boiling-point organic working fluid as the circulating working fluid. TEG refers to Thermovoltaic Power Generation, a power generation method that directly converts temperature difference into electrical energy using the Seebeck effect of thermoelectric materials. In this application, the thermovoltaic power generation component refers to a component that integrates heat exchange and thermoelectric power generation functions, undertaking both heat exchange (preheating, reheating) and thermoelectric power generation functions. The heat source loop refers to the closed loop through which the fluid from heat source 2 flows; the organic working fluid loop refers to the closed loop through which the organic working fluid flows; the cold source loop refers to the closed loop through which the cooling medium flows. The low-temperature working fluid refers to the liquid or gas-liquid mixture working fluid in the organic working fluid loop that has not yet entered the evaporator and is in a relatively low-temperature state; the high-temperature working fluid refers to the working fluid that still carries residual heat after expansion by the turbine generator. Energy-consuming equipment refers to equipment that consumes electrical energy for system operation, such as pump 1 and / or cooling tower 9.

[0026] The following will further describe one or more embodiments of this application with reference to specific examples.

[0027] Example 1: Reference Figure 1As shown, this application provides an ORC-TEG combined geothermal power generation system. This system is applicable to high-temperature fluids, such as geothermal fluids and industrial waste heat fluids, as well as other medium- and low-temperature thermal energy resources. It includes a heat source loop, an organic working fluid loop, and a TEG-preheater 3 connected to both loops and a TEG-regenerator 7 connected to the organic working fluid loop. Specifically, a heat source 2 and an evaporator are connected in series in the heat source loop, with the heat source 2 providing a medium- and low-temperature heat source for the entire system. An evaporator, a turbine generator, and a condenser 8 are connected in series in the organic working fluid loop, forming a complete organic Rankine cycle. Both the TEG-preheater 3 and the TEG-regenerator 7 are thermoelectric power generation components, each including a cold-end heat exchanger 10, a hot-end heat exchanger 11, and several thermoelectric modules 12 sandwiched between them. In this embodiment, the TEG-preheater 3 and the TEG-regenerator 7 have the same structure, differing only in the type of medium introduced into the cold-end heat exchanger 10 and the hot-end heat exchanger 11. In the entire system, the hot-end heat exchanger 11 of the TEG-preheater 3 carries the high-temperature fluid from the heat source circuit (as the hot end), while the cold-end heat exchanger 10 carries the low-temperature working fluid from the ORC (as the cold end). In the TEG-regenerator 7, the hot-end heat exchanger 11 carries the high-temperature working fluid with a large amount of residual heat after passing through the expander (as the hot end), while the cold-end heat exchanger 10 carries the condensed low-temperature working fluid (as the cold end).

[0028] In the heat source loop, the high-temperature heat source 2 first enters the evaporator to release heat, thereby heating the organic working medium in the evaporation organic working medium loop. It then flows through the hot-end heat exchanger 11 of the TEG-preheater 3 to preheat the low-temperature working medium that has been condensed by the condenser 8 but has not yet entered the evaporator. Finally, it flows back to the heat source 2, achieving cascade utilization of the heat from the heat source 2. In the organic working medium loop, the low-temperature working medium from the condenser 8 outlet flows sequentially through the cold-end heat exchanger 10 of the TEG-regenerator 7 and the cold-end heat exchanger 10 of the TEG-preheater 3 before entering the evaporator. In the evaporator, it exchanges heat with the high-temperature heat source 2 to become a high-temperature working medium, which then enters the turbine generator. The turbine generator includes a connected expander and a generator, with the expander driving the generator to generate electricity. The high-temperature working medium at the expander outlet carries a large amount of residual heat and continues to flow through the hot-end heat exchanger 11 of the TEG-regenerator 7 before entering the condenser 8.

[0029] Therefore, the hot end of the TEG-preheater 3 is the high-temperature fluid in the heat source circuit, and the cold end is the low-temperature working fluid in the organic working fluid circuit that has not yet entered the evaporator; the hot end of the TEG-regenerator 7 is the high-temperature working fluid that still carries a large amount of residual heat after the turbine generator expands, and the cold end is the low-temperature working fluid after being condensed by the condenser 8. The two thermoelectric power generation components use the organic working fluid flowing through the cold end heat exchanger 10 as the cooling medium, and utilize the temperature difference between the cold end heat exchanger 10 and the hot end heat exchanger 11 to generate electrical energy in the thermoelectric module 12, and supply the electrical energy to the energy-consuming equipment in the heat source circuit and / or the organic working fluid circuit.

[0030] Therefore, heat transfer between the heat source circuit and the organic working fluid circuit is achieved through the evaporator. Simultaneously, the TEG-preheater 3 is connected between the heat source circuit and the organic working fluid circuit, and the TEG-regenerator 7 is connected in series in the organic working fluid circuit, integrating the thermal photovoltaic power generation components into the preheating and reheating stages of the ORC system. The high-temperature fluid from heat source 2 first releases heat in the evaporator to evaporate the organic working fluid, and then enters the hot-end heat exchanger 11 of the TEG-preheater 3 to preheat the low-temperature working fluid that has not yet entered the evaporator, achieving cascaded utilization of heat from heat source 2. At the same time, the high-temperature exhaust gas from the turbine generator enters the hot-end heat exchanger 11 of the TEG-regenerator 7 to reheat the low-temperature working fluid at the outlet of the condenser 8, achieving cascaded utilization of the working fluid's waste heat. Therefore, the thermoelectric power generation module uses the organic working fluid itself as the cold end cooling medium, eliminating the need for additional cooling systems and circulation equipment. This avoids additional power consumption, realizes energy recovery during preheating and reheating processes, and utilizes the thermoelectric module 12 to convert the temperature difference between the hot and cold ends into electrical energy to supply the energy-consuming equipment inside the system, thereby improving the net power generation and comprehensive energy utilization efficiency of the combined system.

[0031] This embodiment further explains the cyclic connection relationship between the heat source circuit, the organic working fluid circuit, and the cold source circuit.

[0032] In the heat source loop, the outlet of heat source 2 is connected to the inlet of the first pump 1, the outlet of the first pump 1 is connected to the inlet of heat source 2 of the evaporator, the outlet of heat source 2 of the evaporator is connected to the hot-end fluid inlet manifold 13 of the hot-end heat exchanger 11 of the TEG-preheater 3, and the hot-end fluid outlet manifold 14 of the hot-end heat exchanger 11 of the TEG-preheater 3 is connected to the inlet of heat source 2. The first pump 1 is used to drive the fluid of heat source 2 to circulate in the heat source loop.

[0033] In the organic working fluid loop, the outlet of the second pump 1 is connected to the cold-end fluid inlet manifold 15 of the cold-end heat exchanger 10 of the TEG-regenerator 7; the cold-end fluid outlet manifold 16 of the cold-end heat exchanger 10 of the TEG-regenerator 7 is connected to the cold-end fluid inlet manifold 15 of the cold-end heat exchanger 10 of the TEG-preheater 3; the cold-end fluid outlet manifold 16 of the cold-end heat exchanger 10 of the TEG-preheater 3 is connected to the working fluid inlet of the evaporator; the working fluid outlet of the evaporator is connected to the inlet of the expander; the outlet of the expander is connected to the hot-end fluid inlet manifold 13 of the hot-end heat exchanger 11 of the TEG-regenerator 7; the hot-end fluid outlet manifold 14 of the hot-end heat exchanger 11 of the TEG-regenerator 7 is connected to the inlet of the condenser 8; and the outlet of the condenser 8 is connected to the inlet of the second pump 1. The second pump 1 is used to drive the organic working fluid to circulate in the organic working fluid loop.

[0034] The system in this embodiment also includes a cold source loop. In the cold source loop, the outlet of the third pump 1 is connected to the inlet of the condenser 8, the outlet of the condenser 8 is connected to the inlet of the cooling tower 9, and the outlet of the cooling tower 9 is connected to the inlet of the third pump 1. The third pump 1 is used to drive the cooling medium to circulate in the cold source loop, and the cooling tower 9 is used to dissipate heat from the cooling medium.

[0035] Furthermore, the thermoelectric power generation components (TEG-preheater 3 and TEG-regenerator 7) are electrically connected to at least one of the first pump 1, the second pump 1, and the third pump 1, and / or the cooling tower 9, so as to directly supply the electrical energy generated by the thermoelectric module 12 to the corresponding pump 1 and / or cooling tower 9. It should be noted that the electrical connection here refers to a conductive connection for transmitting electrical energy, so that the electrical energy generated by the thermoelectric power generation components can supply the operation of energy-consuming equipment such as pump 1 and / or cooling tower 9.

[0036] Therefore, by using the first pump 1, the second pump 1, and the third pump 1 to drive the circulation of the heat source 2 fluid, organic working fluid, and cooling medium, respectively, and by directly supplying the electrical energy generated by the TEG power generation component to the pump 1 and / or the cooling tower 9, the waste heat and electrical energy recovered by the TEG can be directly used to offset the auxiliary power consumption inside the system, thereby further improving the net power generation of the combined system. Power can be supplied to the energy-consuming equipment inside the system without the need for additional external power supply.

[0037] Example 2: like Figure 2 As shown, this application provides a thermoelectric power generation module for the ORC-TEG combined geothermal power generation system mentioned in Embodiment 1. In this thermoelectric power generation module, the cold-end heat exchanger 10 is annular, with multiple sets of cold flow channels formed along its annular contour. Each set of cold flow channels includes an axially extending cold flow channel 101. The hot-end heat exchanger 11 is plate-shaped, with an axially extending hot flow channel 111 inside. Multiple hot-end heat exchangers 11 and thermoelectric modules 12 are provided, with each thermoelectric module 12 correspondingly sandwiched between the location of each set of cold flow channels in the cold-end heat exchanger 10 and the corresponding hot-end heat exchanger 11. The cold-end heat exchanger 10 receives a low-temperature fluid, while the hot-end heat exchanger 11 receives a high-temperature fluid. The thermoelectric modules 12, each correspondingly sandwiched between the location of each set of cold flow channels in the cold-end heat exchanger 10 and the corresponding hot-end heat exchanger 11, generate electricity using the temperature difference between the cold-end heat exchanger 10 and the hot-end heat exchanger 11.

[0038] This embodiment uses an annular cold-end heat exchanger 10, which allows thermoelectric modules 12 to be arranged on the inner and outer sides of any sidewall of the annular contour. Compared with the conventional pipeline TEG layout, this significantly increases the total number of thermoelectric modules 12, thereby increasing the total power generation of the TEG with the same component volume and improving the system's compactness and power generation efficiency.

[0039] like Figure 4 As shown in the illustration, this embodiment further describes the specific structure of the cold-end heat exchanger 10. The cold-end heat exchanger 10 has a flow-diverting annular cavity 17 and a flow-collecting annular cavity 18 at both ends. The flow-diverting annular cavity 17 is connected to the cold-end fluid inlet manifold 15, and the flow-collecting annular cavity 18 is connected to the cold-end fluid outlet manifold 16. Multiple sets of cold flow channels 101 are connected between the flow-diverting annular cavity 17 and the flow-collecting annular cavity 18. The cold-end fluid inlet manifold 15 is connected to the cold-end fluid outlet manifold 16 of the TEG-regenerator 7's cold-end heat exchanger 10. The cold-end fluid enters the flow-diverting annular cavity 17 through the cold-end fluid inlet manifold 15, is distributed by the flow-diverting annular cavity 17 to multiple sets of cold flow channel groups, and then enters the corresponding cold flow channel 101 within each set of cold flow channel groups. After heat exchange is completed in the cold flow channel 101, the fluid flows into the flow-collecting annular cavity 18 and then out through the cold-end fluid outlet manifold 16. The cold-end fluid inlet manifold 15 and the cold-end fluid outlet manifold 16 can be located on the same side wall or on different side walls. Preferably, the cold-end fluid inlet manifold 15 and the cold-end fluid outlet manifold 16 are located on the same side wall. Furthermore, the cold-end heat exchanger 10 has a fixing base 20 on the symmetrical plane of the cold-end fluid inlet manifold 15 and the cold-end fluid outlet manifold 16, and the fixing base 20 is used to fix the cold-end heat exchanger 10 in the installation position.

[0040] When the photovoltaic (PV) generator is connected in series to the heat source circuit, it acts as the TEG preheater 3. Its cold-end fluid outlet manifold 16 is connected to the working fluid inlet of the evaporator, and its cold-end fluid inlet manifold 15 is connected to the cold-end fluid outlet manifold 16 of the cold-end heat exchanger 10 of the TEG regenerator 7. When the PV generator is connected in series to the organic working fluid circuit, it acts as the TEG regenerator 7. Its cold-end fluid outlet manifold 16 is connected to the outlet of the condenser 8. The cold-end fluid is the low-temperature working fluid condensed by the condenser 8 in the organic working fluid circuit.

[0041] Furthermore, the ring is a polygon, and each set of cold flow channels corresponds to each side wall of the polygon; the plate shape is a flat plate, and the plate surface profile of the flat plate fits the wall surface profile of the side wall to reduce the contact thermal resistance between the cold end heat exchanger 10 and the hot end heat exchanger 11.

[0042] Furthermore, the cold flow channels 101 within each sidewall are direct-flow channels, and the number of direct-flow channels in the sidewalls furthest from the cold-end fluid inlet and outlet increases sequentially to ensure uniform flow distribution across each sidewall. It should be noted that the cold-end fluid inlet and outlet refer to the locations of the cold-end fluid inlet manifold 15 and the cold-end fluid outlet manifold 16. Since the cold-end fluid inlet manifold 15 and the cold-end fluid outlet manifold 16 are located at the same end of the cold-end heat exchanger 10, the flow channels within the sidewall closer to this end are shorter and have lower flow resistance, while the flow channels within the sidewall farther from this end are longer and have higher flow resistance. Therefore, increasing the number of direct-flow channels in the sidewalls furthest from the cold-end fluid inlet and outlet compensates for the resistance differences caused by the differences in flow channel length, thereby ensuring uniform flow distribution across each sidewall.

[0043] This embodiment employs a split-flow annular cavity 17 and a collecting annular cavity 18 in conjunction with the cold-end fluid inlet and outlet manifolds to achieve uniform distribution and collection of the cold-end fluid, ensuring uniform liquid supply from multiple sets of cold flow channels 101 connected in parallel. A polygonal annular cold-end heat exchanger 10 is used, and the plate surface contour of the flat hot-end heat exchanger 11 is made to fit closely with the sidewall contour, increasing the heat exchange contact area and reducing contact thermal resistance. A direct-flow channel is used, with the number of direct-flow channels in the sidewalls furthest from the cold-end fluid inlet and outlet increasing sequentially. This avoids uneven flow distribution caused by differences in channel length, improves the problem of localized overcooling or overheating at the heat exchange interface, and ensures uniform surface temperature distribution of the cold-end heat exchanger 10, thereby improving the power generation efficiency and stability of the TEG.

[0044] like Figures 5-7 As shown, this embodiment further illustrates the specific structure of the hot-end heat exchanger 11. The two ends of the hot-end heat exchanger 11 are connected to the hot-end fluid inlet manifold 13 and the hot-end fluid outlet manifold 14 respectively via flexible hoses 19. The flow holes 113 on the hot-end fluid inlet manifold 13 and the hot-end fluid outlet manifold 14 are arranged circumferentially to facilitate the installation and maintenance of the flexible hoses 19. After being distributed through the hot-end fluid inlet manifold 13, the hot-end fluid enters each hot-end heat exchanger 11 through the flexible hoses 19. After heat exchange is completed in each hot-end heat exchanger 11, the fluid flows out through the flexible hoses 19 and merges into the hot-end fluid outlet manifold 14. Furthermore, the plate shape is flat, and the outline of the flat plate conforms to the outline of the polygonal sidewall. Furthermore, the hot flow channel 111 within the hot-end heat exchanger 11 is a direct-flow channel, and a conical header 112 with a flow-dividing structure is provided at the fluid inlet. The conical header 112 is configured to uniformly distribute the fluid entering the hot-end heat exchanger 11 to each direct-flow channel. The fluid is either a high-temperature heat source 2 or a high-temperature working fluid expanded by a turbine generator. The conical contraction structure of the conical header 112 causes the fluid to gradually accelerate along the flow direction and be uniformly distributed to each direct-flow channel.

[0045] In this embodiment, a flexible hose 19 is used to connect the hot-end heat exchanger 11 to the hot-end fluid inlet and outlet manifold, and the flow holes 113 are arranged in a circular pattern to facilitate the installation, maintenance, and replacement of the hose 19, reducing assembly difficulty. A conical header 112 with a flow-dividing structure is used to evenly distribute the fluid to each direct-flow channel at the inlet, avoiding uneven heat exchange caused by inlet flow deviation, thus improving the heat exchange efficiency of the hot-end heat exchanger 11 and the power generation stability of the TEG.

[0046] In a preferred embodiment of this application, the thermal photovoltaic (TEG) power generation module employs a staggered counter-flow heat exchange structure design on both sides. That is, the cold-end fluid and the hot-end fluid flow in opposite directions between the cold-end heat exchanger 10 and the hot-end heat exchanger 11 to improve the heat exchange efficiency between the cold and hot ends, thereby further improving the thermoelectric conversion efficiency of the TEG. Exemplarily, the cold-end fluid inlet manifold 15 and the cold-end fluid outlet manifold 16 are axially spaced from the first end to the second end at opposite ends of the cold-end heat exchanger 10, and the hot-end fluid inlet manifold 13 and the hot-end fluid outlet manifold 14 are axially spaced from the second end to the first end at opposite ends of the hot-end heat exchanger 11.

[0047] As an optional embodiment of this application, the cold flow channels 101 in each sidewall of the cold-end heat exchanger 10 are direct-flow channels with a circular cross-section, and the hot flow channels 111 in the hot-end heat exchanger 11 are direct-flow channels with a rectangular cross-section. Furthermore, rib structures are provided between adjacent direct-flow channels in the hot-end heat exchanger 11. The rib structures improve the overall rigidity of the hot-end heat exchanger 11 and reduce the risk of bending and deformation of the hot-end heat exchanger 11 as its length increases.

[0048] In a preferred embodiment, such as Figure 3 As shown, a flat-plate hot-end heat exchanger 11 is arranged on both the inner and outer sides of each sidewall, and two hot-end heat exchangers 11 located on the same sidewall are arranged in a mirror image relative to the sidewall. Each set of two mirror-arranged hot-end heat exchangers 11 is fixed to the cold-end heat exchanger 10 with fasteners, and a thermoelectric module 12 is sandwiched between the sidewall and each hot-end heat exchanger 11. Thus, the thermoelectric module 12 can generate electricity using the temperature difference between the cold-end heat exchanger 10 and the hot-end heat exchanger 11. The mirror arrangement, with one hot-end heat exchanger 11 on both the inner and outer sides of each sidewall and one thermoelectric module 12 sandwiched between them, fully utilizes the heat exchange area on both sides of the sidewall, further increasing the number of thermoelectric modules 12. Using fasteners to fix the hot-end heat exchangers 11 to the cold-end heat exchanger 10 gives the hot-end heat exchangers 11 the function of clamping plates, simplifying the assembly process and ensuring a smoother fit between the heat exchange interface and the thermoelectric module 12.

[0049] As an optional embodiment of this application, in the polygonal cold-end heat exchanger 10, in addition to the side wall in which two hot-end heat exchangers 11 are arranged symmetrically in mirror image, the side wall with the fixed base 20 and the side wall with the cold-end fluid inlet and outlet manifold can be a non-circular hot-end heat exchanger 11 with a relatively short length and the cold-end fluid inlet and outlet located on the outer side of the heat exchanger. The non-circular hot-end heat exchanger 11 is provided on the inner side of the side wall where the fixed base 20 and the cold-end fluid inlet and outlet are located.

[0050] In some embodiments, a shorter hot-end heat exchanger 11 may be provided at a location that avoids the fixed base 20 and the cold-end fluid inlet and outlet, forming two hot-end heat exchangers 11 arranged asymmetrically in mirror at the side wall.

[0051] As a preferred embodiment of this application, the ports of the hot-end fluid inlet manifold 13 and the hot-end fluid outlet manifold 14 are designed with flanges to facilitate connection with the system fluid pipeline.

[0052] Furthermore, a thermally conductive interface material is coated between the cold-end heat exchanger 10 and the thermoelectric module 12, and between the hot-end heat exchanger 11 and the thermoelectric module 12, to reduce the contact thermal resistance between the cold-end heat exchanger 10, the hot-end heat exchanger 11 and the thermoelectric module 12.

[0053] Furthermore, each sidewall surface of the cold-end heat exchanger 10 and the surface of the hot-end heat exchanger 11 are provided with limiting grooves for accommodating the thermoelectric module 12. Through holes 22 are provided on both sides of the limiting grooves. Fastening bolts 21 pass through the through holes 22 to press the hot-end heat exchanger 11 against the outside of the thermoelectric module 12, thus enabling the hot-end heat exchanger 11 to also function as a clamping plate. Nuts 23 are pre-welded to the surface of the hot-end heat exchanger 11 located inside the cold-end heat exchanger 10. The nuts 23 cooperate with the fastening bolts 21 to lock the assembly, thus solving the problem of difficult assembly operations due to the narrow space inside the cold-end heat exchanger 10. As an optional embodiment of this application, the axial length of the thermoelectric power generation component can be flexibly adjusted to meet the load and power demand of heat sources 2 of different scales.

[0054] Along the axial direction of the thermal photovoltaic power generation module, multiple sets of fasteners consisting of fastening bolts 21, through holes 22 and nuts 23 can be installed to securely connect the long thermal photovoltaic power generation module from the outside to the inside in the axial direction.

[0055] In some embodiments, the side of the cold-end heat exchanger 10 and the hot-end heat exchanger 11 facing the thermoelectric module 12 may not have a limiting groove. A limiting groove may be provided on either the cold-end heat exchanger 10 or the hot-end heat exchanger 11.

[0056] Example 3: It should be noted that the system provided in Embodiment 1 and the thermoelectric power generation component provided in Embodiment 2 can be implemented individually or in combination. When implemented in combination, the thermoelectric power generation component preferably serves as both the TEG preheater 3 and the TEG regenerator 7 of the system. The number of thermoelectric modules 12, the type of semiconductor material, and the array arrangement can be adjusted according to power generation requirements. The shape, structure type, and size of each heat exchanger in the system, as well as the number and shape of the cold and hot heat exchanger channels, can all be changed. Different types of organic working fluid and high-temperature heat source 2 can be selected. When implemented individually, the heat source 2 in the hot-end heat exchanger 11 can also be municipal / domestic waste heat, etc., and the cold-end working fluid in the cold-end heat exchanger 10 can also be circulating water from the cooling tower 9, river water, lake water, seawater, and industrial circulating coolant, etc.

[0057] Example 4: The following provides a specific and complete embodiment to illustrate this application.

[0058] Please continue reading. Figures 1-7 The thermal photovoltaic (TPV) generator also serves as the TEG preheater 3 and TEG regenerator 7 in the ORC combined geothermal power generation system. The cold-end heat exchanger 10 is a hexagonal cold-end heat exchanger 10 with a regular hexagonal cross-section, extending axially in a hexagonal prism shape. For ease of description, the six sidewalls of this hexagonal cold-end heat exchanger 10 are respectively labeled as the upper sidewall, lower sidewall, left front oblique sidewall, right front oblique sidewall, left rear oblique sidewall, and right rear oblique sidewall, and the two ends along the axial direction are respectively labeled as the front end and the rear end.

[0059] For the cold-end fluid, the cold-end fluid inlet manifold 15 is located on the upper side wall near the front end, and the cold-end fluid outlet manifold 16 is located on the upper side wall near the rear end. The hexagonal cold-end heat exchanger 10 has a hexagonal flow-dividing annular cavity 17 at its front end and a hexagonal flow-collecting annular cavity 18 at its rear end. The hexagonal flow-dividing annular cavity 17 is connected to the cold-end fluid inlet manifold 15, and the hexagonal flow-collecting annular cavity 18 is connected to the cold-end fluid outlet manifold 16. Each side wall has an axially extending circular cross-section direct-flow channel (i.e., a cold flow channel 101). The front end of each cold flow channel 101 is connected to the hexagonal flow-dividing annular cavity 17, and the rear end is connected to the hexagonal flow-collecting annular cavity 18. Since the cold-end fluid inlet and outlet manifolds are located on the upper side wall, the number of cold flow channels 101 located in the side walls furthest from the upper side wall (i.e., furthest from the cold-end fluid inlet and outlet manifolds) increases sequentially to ensure uniform flow distribution across all side walls. For example, the upper side wall has nine cold flow channels 101, the two front inclined side walls each have ten cold flow channels 101, and the two rear and front inclined side walls and the lower side wall each have twelve cold flow channels 101. The fixed base 20 is provided on the lower side wall, that is, on the symmetrical plane of the upper side wall, and one is provided on each of the front and rear sides of the lower side wall, for fixing the hexagonal cold end heat exchanger 10 in the installation position.

[0060] Regarding the hot-end fluid, the hot-end fluid inlet manifold 13 is located behind the hexagonal cold-end heat exchanger 10, and the hot-end fluid outlet manifold 14 is located in front. The manifolds of both are arranged in a circular pattern, and the pipe openings are designed with flanges. There are a total of ten flat plate hot-end heat exchangers 11. Eight flat plate hot-end heat exchangers 11 are arranged on four inclined walls, with one flat plate hot-end heat exchanger 11 arranged on the inner and outer sides of each inclined wall. The two flat plate hot-end heat exchangers 11 located on opposite sides of the same inclined wall are arranged in a mirror image relative to that inclined wall. The two flat plate hot-end heat exchangers 11 are arranged on the upper and lower side walls, respectively. Since the upper side wall has the cold-end fluid inlet and outlet manifolds and the lower side wall has the fixed base 20, the available heat exchange area is limited. Therefore, these two side walls adopt a relatively short-length, irregularly shaped hot-end heat exchanger 11 with the cold-end fluid inlet and outlet located on the side of the heat exchanger. Each hot-end heat exchanger 11 has a rectangular cross-section direct-flow channel (i.e., hot flow channel 111) extending axially, and a conical header 112 with a flow-dividing structure at its fluid inlet. The rear end of each hot-end heat exchanger 11 is connected to the hot-end fluid inlet manifold 13 via a hose 19, and the front end is connected to the hot-end fluid outlet manifold 14 via a hose 19. There are ten sets of thermoelectric modules 12, which are sandwiched between each side wall and the corresponding hot-end heat exchanger 11. Specifically, in the four inclined side walls, one set of thermoelectric modules 12 is sandwiched on the inner and outer sides of each inclined side wall, for a total of eight sets; and one set of thermoelectric modules 12 is sandwiched on each of the upper and lower side walls, for a total of two sets. Each set of thermoelectric modules 12 generates electrical energy using the temperature difference between its side wall and the corresponding hot-end heat exchanger 11.

[0061] Each side wall surface of the hexagonal cold-end heat exchanger 10 and the surface of each hot-end heat exchanger 11 are machined with limiting grooves for accommodating the thermoelectric module 12. Each limiting groove has at least one through hole 22 on both sides. Fastening bolts 21 pass through the through holes 22 to press the hot-end heat exchanger 11 against the outside of the thermoelectric module 12, thus enabling the hot-end heat exchanger 11 to also function as a clamping plate. Nuts 23 are pre-welded to the surface of the hot-end heat exchanger 11 located inside the hexagonal cold-end heat exchanger 10 (i.e., the flat plate hot-end heat exchanger 11 on the inner side of the four inclined walls). The nuts 23 engage with the fastening bolts 21 to lock the hot-end heat exchanger 11 in place, thus solving the problem of difficult assembly and operation due to the narrow space inside the hexagonal cold-end heat exchanger 10. A thermally conductive interface material is coated between the cold-end heat exchanger 10 and the thermoelectric module 12, and between the hot-end heat exchanger 11 and the thermoelectric module 12.

[0062] During operation, the cold-end fluid (e.g., the low-temperature working fluid condensed by the condenser 8) enters the hexagonal distribution ring cavity 17 from the cold-end fluid inlet manifold 15. It is then distributed by the hexagonal distribution ring cavity 17 to the cold flow channels 101 on each side wall. After axially flowing from front to back through each cold flow channel 101 to complete heat exchange, it merges into the hexagonal collector ring cavity 18 and then flows out through the cold-end fluid outlet manifold 16. The hot-end fluid (e.g., the high-temperature geothermal source 2 or the high-temperature working fluid expanded by the turbine generator) is distributed from the hot-end fluid inlet manifold 13 through the hose 19 to the hot flow channels 111 of each hot-end heat exchanger 11. It flows axially from back to front through each hot flow channel 111 and then merges into the hot-end fluid outlet manifold 14 through the hose 19. The cold-end and hot-end fluids form a staggered counter-flow heat exchange structure at each side wall to improve the heat exchange efficiency between the cold and hot ends. Each set of thermoelectric modules 12 sandwiched between the side wall and the hot end heat exchanger 11 generates electrical energy by utilizing the temperature difference between the two sides. The electrical energy is collected and supplied to energy-consuming equipment such as pumps 1 and / or cooling towers 9 inside the system.

[0063] The embodiments of this application have at least the following beneficial effects: First, by integrating the thermal photovoltaic power generation components into the TEG-preheater 3 and TEG-regenerator 7 of the ORC system, and using the organic working fluid itself as the cold-end cooling medium, no additional cooling system and circulation equipment are required, eliminating the extra power consumption of the cooling system. At the same time, the waste heat of heat source 2 and working fluid is recovered during the preheating and reheating process for cascade power generation, and the electrical energy is supplied to the energy-consuming equipment inside the system, thereby improving the net power generation and comprehensive energy utilization efficiency of the combined system.

[0064] Secondly, the cold end heat exchanger 10 of the thermal photovoltaic power generation component adopts a hexagonal design, and thermal power modules 12 can be arranged on both the inner and outer sides of each side. Compared with the conventional pipeline TEG layout method, this greatly increases the number of thermal power modules 12, further improving the system's compactness and power generation efficiency.

[0065] Third, the hexagonal cold-end heat exchanger has circular hole cross-section direct current channels in all 10 side walls, far away from the cold-end fluid inlet main pipe. The number of circular hole channels in the side walls increases sequentially. Compared with the uniformly arranged flow channels in traditional heat exchangers, the flow distribution on each side is more uniform, which improves the problem of local overcooling or overheating at the heat exchange interface, thereby improving the power generation efficiency and stability of TEG.

[0066] Fourth, the flat plate heat exchanger 11 has a rectangular cross-section direct current channel inside and a conical header 112 with a flow splitting structure at the inlet. Compared with conventional rectangular cavity heat exchangers, this design enables efficient and uniform flow distribution while improving the overall structural rigidity of the heat exchanger, thus avoiding the risk of bending and deformation due to increased component length or high-temperature stress concentration.

[0067] Fifth, the surfaces of the hot and cold end heat exchangers are provided with thermoelectric module 12 limiting grooves, and through holes 22 for fastening bolts 21 are provided on both sides of the limiting grooves, so that the flat plate heat exchanger 11 has the function of clamping pressure plate. At the same time, nuts 23 are pre-welded on the inner surface of the flat plate heat exchanger 11. Compared with the traditional method of relying on external buckles or auxiliary clamps, this design simplifies the assembly process and makes the heat exchange interface fit more smoothly with TEG.

[0068] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0069] It should also be noted that, in this document, the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations, nor should they be construed as indicating or implying relative importance. Moreover, the term "comprising" or any other variation thereof is intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements, but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device.

[0070] The ORC-TEG combined geothermal power generation system provided in this application has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand this application, and the content of this specification should not be construed as a limitation of this application. Furthermore, for those skilled in the art, there will be different forms of changes in the specific implementation methods and application scope based on this application. It is neither necessary nor possible to exhaustively list all implementation methods here, and obvious variations or modifications derived therefrom are still within the protection scope of this application.

Claims

1. An ORC-TEG combined geothermal power generation system, characterized in that, The system includes: A heat source circuit, wherein a heat source and an evaporator are connected in series in the heat source circuit; An organic working fluid circuit, wherein the evaporator, turbine generator and condenser are provided on the organic working fluid circuit; The heat source circuit and the organic working fluid circuit share a TEG preheater, and the organic working fluid circuit is also equipped with a TEG regenerator; both the TEG preheater and the TEG regenerator are thermoelectric power generation components, and the thermoelectric power generation components include a cold end heat exchanger, a hot end heat exchanger, and several thermoelectric modules sandwiched between the two. The hot end heat exchanger of the TEG preheater is connected to the heat source circuit between the heat source and the evaporator, and its cold end heat exchanger is connected to the organic working fluid circuit between the evaporator and the cold end heat exchanger of the TEG regenerator. The hot end heat exchanger of the TEG-regenerator is connected to the organic working fluid circuit between the turbine generator and the condenser, and its cold end heat exchanger is connected to the organic working fluid circuit between the condenser and the cold end heat exchanger of the TEG-preheater. The TEG-regenerator uses the high-temperature working fluid with residual heat after expansion by the turbine generator in the organic working fluid circuit as the hot end and the low-temperature working fluid after condensation by the condenser in the organic working fluid circuit as the cold end; the TEG-preheater uses the high-temperature heat source in the heat source circuit as the hot end and the low-temperature working fluid in the organic working fluid circuit as the cold end; the two thermoelectric power generation components respectively utilize the temperature difference between the cold end heat exchanger and the hot end heat exchanger to generate electricity from the thermoelectric module and supply power to at least one energy-consuming device in the heat source circuit and the organic working fluid circuit.

2. The ORC-TEG combined geothermal power generation system according to claim 1, characterized in that, In the heat source circuit, the heat source, the first pump, the evaporator, and the hot-end heat exchanger of the TEG-preheater are sequentially and circulated in a loop. In the organic working fluid circuit, the second pump, the cold end heat exchanger of the TEG-regenerator, the cold end heat exchanger of the TEG-preheater, the evaporator, the turbine generator, the hot end heat exchanger of the TEG-regenerator, and the condenser are sequentially connected in a loop.

3. The ORC-TEG combined geothermal power generation system according to claim 2, characterized in that, The system also includes: A cold source circuit, wherein a third pump, the condenser and the cooling tower are sequentially connected in a circulating manner; The thermoelectric power generation component is electrically connected to at least one of the first pump, the second pump, and the third pump, and / or the cooling tower, so as to directly supply the generated electrical energy to the corresponding pump and / or the cooling tower.

4. An ORC-TEG combined geothermal power generation system according to any one of claims 1-3, characterized in that, In the aforementioned thermoelectric power generation module: The cold-end heat exchanger is annular, and multiple sets of cold flow channels are formed inside along the annular contour. Each set of cold flow channels includes a cold flow channel extending along the axial direction. The hot-end heat exchanger is plate-shaped and has an axially extending hot flow channel inside. Multiple hot-end heat exchangers and thermoelectric modules are provided, and each thermoelectric module is sandwiched between the location of each group of cold flow channels of the cold-end heat exchanger and the corresponding hot-end heat exchanger.

5. The ORC-TEG combined geothermal power generation system according to claim 4, characterized in that, The cold-end heat exchanger is provided with a flow-dividing ring cavity and a flow-collecting ring cavity at both ends. The flow-dividing ring cavity is connected to the cold-end fluid inlet manifold, and the flow-collecting ring cavity is connected to the cold-end fluid outlet manifold. A plurality of cold flow channels are connected between the flow-dividing ring cavity and the flow-collecting ring cavity. The cold-end heat exchanger is provided with a fixed base on the symmetrical plane of the cold-end fluid inlet manifold and the cold-end fluid outlet manifold.

6. The ORC-TEG combined geothermal power generation system according to claim 4, characterized in that, The two ends of the hot-end heat exchanger are connected to the hot-end fluid inlet manifold and the hot-end fluid outlet manifold respectively via flexible hoses, and the flow holes on the hot-end fluid inlet manifold and the hot-end fluid outlet manifold are arranged in a circular pattern.

7. The ORC-TEG combined geothermal power generation system according to claim 4, characterized in that, The ring includes a polygon, and each group of cold runners corresponds to each sidewall of the polygon; the plate shape includes a flat plate shape, and the plate surface profile of the flat plate shape fits the wall surface profile of the sidewall.

8. The ORC-TEG combined geothermal power generation system according to claim 7, characterized in that, Each of the inner and outer ring edges of each of the sidewalls is provided with a flat plate-shaped heat exchanger, and the two heat exchangers located on both sides of the same sidewall are arranged in a mirror image relative to the sidewall. In this configuration, two hot-end heat exchangers arranged in a mirror image are radially fixed to the cold-end heat exchanger by fasteners, and each set of thermoelectric modules is sandwiched between each sidewall and each hot-end heat exchanger.

9. The ORC-TEG combined geothermal power generation system according to claim 7, characterized in that, The cold flow channels within each of the side walls are direct flow channels, and the number of direct flow channels within the side walls furthest from the cold end fluid inlet manifold increases sequentially to ensure uniform flow distribution across each side wall. The hot flow channel in the hot end heat exchanger is a direct flow channel, and a conical header with a flow splitting structure is provided at the fluid inlet. The conical header is configured to distribute the fluid entering the hot end heat exchanger evenly to each of the direct flow channels. The fluid refers to the high-temperature working fluid or the high-temperature heat source.

10. An ORC-TEG combined geothermal power generation system according to claim 4, characterized in that, A thermally conductive interface material is coated between the cold-end heat exchanger and the thermoelectric module, and between the hot-end heat exchanger and the thermoelectric module.

Images